1. Field of the Invention
The present invention relates to a multilayer ceramic electronic component, and more particularly, relates to a multilayer ceramic electronic component which includes a ceramic multilayer body formed by stacking ceramic layers, inner electrodes disposed therein, and outer electrodes disposed on surfaces of the ceramic multilayer body so as to be electrically connected to the inner electrodes.
2. Description of the Related Art
As a method for manufacturing a multilayer ceramic capacitor, which is a typical multilayer ceramic electronic component, Japanese Unexamined Patent Application Publication No. 2012-190874 (Patent Document 1) describes a method for manufacturing a multilayer ceramic capacitor as described below.
In the method for manufacturing a multilayer ceramic capacitor according to Patent Document 1, first, first and second green sheets each provided with an unfired inner electrode layer are prepared, the first and second green sheets are alternately stacked such that electrostatic capacity-forming portions of the unfired inner electrode layers are superimposed on one another, and thereby, an unfired ceramic multilayer body is formed.
Then, the unfired ceramic multilayer body is cut into a one-chip region, and the extending portion of each unfired inner electrode layer is exposed to either one of end faces of the unfired ceramic multilayer body. By applying a conductive paste to the end faces of the unfired ceramic multilayer body to which the extending portions of the unfired inner electrode layers are exposed, unfired underlying metal layers are formed.
Then, by firing the unfired ceramic multilayer body, the green sheets, the unfired inner electrode layers, and the unfired underlying metal layers are co-fired, and plating is performed on the surfaces of the fired underlying metal layers.
Thereby, for example, as shown in FIG. 2, a multilayer ceramic electronic component is obtained. The multilayer ceramic electronic component includes a ceramic multilayer body 110 in which a plurality of inner electrodes 102a and a plurality of inner electrodes 102b are alternately disposed with a ceramic layer 101 interposed therebetween, and outer electrodes 104a and 104b are disposed on end faces 103a and 103b of the ceramic multilayer body 110 so as to be electrically connected to the inner electrodes 102a and 102b extending to the different end faces 103a and 103b. 
However, in the manufacturing method of Patent Document 1, outer electrodes are formed by applying the conductive paste to the end faces of the unfired ceramic multilayer body, followed by baking (co-firing with the unfired ceramic multilayer body). Therefore, the thickness of the outer electrodes is large (usually, 10 μm or more), resulting in an increase in the size of the multilayer ceramic capacitor, i.e., finished product, which is a problem.
In particular, in the case of a multilayer ceramic electronic component to be built in a multilayer board or the like in which it is desired to decrease the thickness (height) of the finished product as much as possible, the thickness of the outer electrodes has a non-negligible effect on the thickness (height) of the finished product.
It is conceivable that, by decreasing the specific gravity of the conductive paste, the coating thickness of the conductive paste is decreased (a thin coating is applied). In such a case, electrode continuity is decreased at the ridge portions (corners) of the ceramic multilayer body, resulting in insufficient reliability, which is a problem.
Furthermore, Japanese Patent No. 5287658 (Patent Document 2) discloses a method for manufacturing a ceramic electronic component (multilayer ceramic capacitor according to an embodiment).
In the method of Patent Document 2, first, a predetermined number of ceramic green sheets for outer layers without an inner electrode pattern formed thereon are stacked. Then, a predetermined number of ceramic green sheets with a first inner electrode pattern printed thereon and a predetermined number of ceramic green sheets with a second inner electrode pattern printed thereon are alternately stacked on the stacked ceramic green sheets. Then, a predetermined number of ceramic green sheets for outer layers without an inner electrode pattern formed thereon are further stacked on the stacked ceramic green sheets to produce a mother multilayer body.
Next, outer terminal electrode patterns, which will become first and second outer terminal electrodes, are formed on the upper and lower surfaces of the resulting mother multilayer body by screen printing or the like.
Then, the mother multilayer body is cut at predetermined positions and divided into individual ceramic multilayer bodies (unfired ceramic bodies). Next, each ceramic multilayer body is subjected to barrel polishing, and then, a conductive paste is applied to end faces, followed by baking to form outer terminal electrodes. Thus, a ceramic electronic component is obtained.
In the method for manufacturing a ceramic electronic component (multilayer ceramic capacitor according to an embodiment) described in Patent Document 2, outer terminal electrode patterns, which will become portions of first and second outer terminal electrodes that extend from the end faces to partially surround the upper and lower surfaces (side faces), are formed by a screen printing method or the like. Therefore, it is possible to decrease the thickness of the outer terminal electrodes disposed on the upper and lower surfaces (side faces) of the ceramic multilayer body compared with the case of Patent Document 1 described above, and the thickness (height) of the ceramic electronic component can be decreased.
However, in the method of Patent Document 2, although the thickness of the outer terminal electrodes disposed on the upper and lower surfaces can be decreased, the thickness is decreased to only about 5 μm. If the thickness is further decreased, scraping of the electrodes may occur at the time of the barrel polishing treatment for imparting roundness (R) to the ridge portions after singulation of individual ceramic multilayer bodies has been performed by dividing the mother multilayer body, which may result in plating defects or a decrease in conduction reliability, which is a problem.